PUCCH for MTC devices

ABSTRACT

Methods, systems, and devices are described for wireless communication at a device. A wireless device may be configured with a transmission time interval (TTI) bundling parameter. The device may then identify one or more resources for an uplink (UL) control channel based on the TTI bundling parameter (e.g., using either an implicit or an explicit indication from another wireless node such as a serving cell of a base station) and transmit the UL control channel using the identified resources. The device may also identify a downlink control information (DCI) format based on the TTI bundling parameter. For example, a resource allocation granularity level may be associated with the bundling parameter, and the length of a DCI field may depend on the resource allocation granularity level.

CROSS REFERENCES

The present Application for Patent is a Continuation of U.S. patentapplication Ser. No. 14/926,630 by Chen et al., entitled “PUCCH For MTCDevices” filed Oct. 29, 2015 which claims priority to U.S. ProvisionalPatent Application No. 62/077,064 by Chen et al., entitled “PUCCH forMTC Devices,” filed Nov. 7, 2014, assigned to the assignee hereof, andexpressly incorporated in their entirety by reference herein.

FIELD OF TECHNOLOGY

The following relates generally to wireless communication, and morespecifically to a physical uplink control channel (PUCCH) for machinetype communication (MTC) devices.

BACKGROUND

Wireless communications systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be multiple-accesssystems capable of supporting communication with multiple users bysharing the available system resources (e.g., time, frequency, andpower). Examples of such multiple-access systems include code divisionmultiple access (CDMA) systems, time division multiple access (TDMA)systems, frequency division multiple access (FDMA) systems, andorthogonal frequency division multiple access (OFDMA) systems, (e.g., aLong Term Evolution (LTE) system).

By way of example, a wireless multiple-access communications system mayinclude a number of base stations, each simultaneously supportingcommunication for multiple communication devices, which may be otherwiseknown as user equipment (UEs). A base station may communicate with thecommunication devices on downlink channels (e.g., for transmissions froma base station to a UE) and uplink channels (e.g., for transmissionsfrom a UE to a base station).

In some cases, different UEs may have different wireless linkconfigurations such as different transmission time interval (TTI)bundling configurations. For example, some types of UEs may designed forautomated communication. Automated wireless devices may include thoseimplementing Machine-to-Machine (M2M) communication or Machine TypeCommunication (MTC), i.e., communication without human intervention. MTCdevices and other UEs may implement coverage enhancement operations thatinclude higher levels of repetition or lower modulation and coding (MCS)rates, which may be associated with a number of bundled TTIs for each DLor UL transmission. In some cases, different TTI bundling configurationsmay result in collisions of UL control transmissions.

SUMMARY

The present disclosure may relate generally to wireless communicationssystems, and more particularly to improved systems, methods, orapparatuses for PUCCH with MTC devices. A wireless device may beconfigured with a transmission time interval (TTI) bundling parameter.The device may then identify one or more resources for an uplink (UL)control channel based on the TTI bundling parameter (e.g., using eitheran implicit or an explicit indication from another wireless node such asa serving cell of a base station) and transmit the UL control channelusing the identified resources. The device may also identify a downlinkcontrol information (DCI) format based on the TTI bundling parameter.For example, a resource allocation granularity level may be associatedwith the bundling parameter, and the length of a DCI field may depend onthe resource allocation granularity level.

A method of wireless communication at a wireless device is described.The method may include identifying a TTI bundling parameter of an ULcontrol channel, and identifying one or more resources for the ULcontrol channel based at least in part on the TTI bundling parameter.

An apparatus for wireless communication at a wireless device isdescribed. The apparatus may include means for identifying a TTIbundling parameter of an UL control channel, and means for identifyingone or more resources for the UL control channel based at least in parton the TTI bundling parameter.

A further apparatus for wireless communication at a wireless device isdescribed. The apparatus may include a processor, memory in electroniccommunication with the processor, and instructions stored in the memory,wherein the instructions are executable by the processor to identify aTTI bundling parameter of an UL control channel, and identify one ormore resources for an UL control channel based at least in part on theTTI bundling parameter.

A non-transitory computer-readable medium storing code for wirelesscommunication at a wireless device is described. The code may includeinstructions executable to identify a TTI bundling parameter of an ULcontrol channel, and identify one or more resources for an UL controlchannel based at least in part on the TTI bundling parameter.

Some examples of the method, apparatuses, or non-transitorycomputer-readable medium described above may further include features,means, or instructions for transmitting the UL control channel using theone or more resources. Additionally or alternatively, some examples mayinclude receiving the UL control channel using the one or moreresources.

In some examples of the method, apparatuses, or non-transitorycomputer-readable medium described above, identifying the one or moreresources comprises identifying the one or more resources based on animplicit resource allocation. Additionally or alternatively, in someexamples the implicit resource allocation is based at least in part onat least one of a physical downlink control channel (PDCCH) resource ora physical downlink shared channel (PDSCH) resource.

In some examples of the method, apparatuses, or non-transitorycomputer-readable medium described above, identifying the one or moreresources comprises identifying the one or more resources based at leastin part on a correspondence between a set of frequency ranges of acarrier bandwidth of a serving cell and a set of TTI bundlingparameters, wherein the set of TTI bundling parameters comprises the TTIbundling parameter of the UL control channel. Additionally oralternatively, some examples may include determining a correspondencebetween a set of resource offsets and a set of TTI bundling parameters,wherein the set of TTI bundling parameters comprises the TTI bundlingparameter of the UL control channel.

In some examples of the method, apparatuses, or non-transitorycomputer-readable medium described above, identifying the one or moreresources comprises selecting a resource offset from the set of resourceoffsets based at least in part on the TTI bundling parameter and thecorrespondence. Additionally or alternatively, some examples may includereceiving a configuration indicating a resource offset corresponding tothe TTI bundling parameter, wherein identifying the one or moreresources is based on the resource offset.

In some examples of the method, apparatuses, or non-transitorycomputer-readable medium described above, identifying the one or moreresources comprises receiving an indication of the one or more resourcesfrom a wireless node. Additionally or alternatively, some examples mayinclude receiving a configuration of a plurality of resources for theTTI bundling parameter, receiving an indication in a DL control channel,and identifying one resource from the configured plurality of resourcesfor the TTI bundling parameter based on the indication.

In some examples of the method, apparatuses, or non-transitorycomputer-readable medium described above, identifying the one or moreresources comprises identifying a resource hopping pattern for a bundledtransmission over a plurality of subframes in a resource block.Additionally or alternatively, in some examples the TTI bundlingparameter is based at least in part on a coverage enhancement setting ofthe wireless device.

In some examples of the method, apparatuses, or non-transitorycomputer-readable medium described above, the wireless device is an MTCdevice.

A method of wireless communication at a wireless device is described.The method may include identifying a TTI bundling parameter of an ULcontrol channel, and identifying a DCI format based at least in part onthe TTI bundling parameter.

An apparatus for wireless communication at a wireless device isdescribed. The apparatus may include means for identifying a TTIbundling parameter of an UL control channel, and means for identifying aDCI format based at least in part on the TTI bundling parameter.

A further apparatus for wireless communication at a wireless device isdescribed. The apparatus may include a processor, memory in electroniccommunication with the processor, and instructions stored in the memory,wherein the instructions are executable by the processor to identify aTTI bundling parameter of an UL control channel, and identify a DCIformat based at least in part on the TTI bundling parameter.

A non-transitory computer-readable medium storing code for wirelesscommunication at a wireless device is described. The code may includeinstructions executable to identify a TTI bundling parameter of an ULcontrol channel, and identify a DCI format based at least in part on theTTI bundling parameter.

Some examples of the method, apparatuses, or non-transitorycomputer-readable medium described above may further include features,means, or instructions for receiving a DL control channel based at leastin part on the DCI format. Additionally or alternatively, some examplesmay include transmitting a DL control channel based at least in part onthe DCI format.

In some examples of the method, apparatuses, or non-transitorycomputer-readable medium described above, the TTI bundling parametercorresponds to a resource allocation granularity level, wherein the DCIformat is based at least in part on the resource allocation granularitylevel. Additionally or alternatively, in some examples the resourceallocation granularity level is based on a minimum of a plurality ofresource block (RBs), wherein a DCI field indicating a set of resourcesfor an UL control channel comprises a number bits based on the resourceallocation granularity level.

In some examples of the method, apparatuses, or non-transitorycomputer-readable medium described above, the resource allocationgranularity level is based on a minimum of 1 RB, wherein a DCI fieldindicating a set of resources for an UL control channel comprises anumber of bits based on the resource allocation granularity level.Additionally or alternatively, in some examples the TTI bundlingparameter corresponds to an MCS information field, wherein the DCIformat is based at least in part on the MCS information field.

Some examples of the method, apparatuses, or non-transitorycomputer-readable medium described above may further include features,means, or instructions for determining a first TTI bundling length,determining a first length of the MCS information field based on thefirst TTI bundling length, determining a second TTI bundling length,where the second TTI bundling length is larger than the first TTIbundling length, and determining a second length of the MCS informationfield based on the second TTI bundling length, where the second lengthof the MCS information field is smaller than the first length of the MCSinformation field.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purpose ofillustration and description only, and not as a definition of the limitsof the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the presentdisclosure may be realized by reference to the following drawings. Inthe appended figures, similar components or features may have the samereference label. Further, various components of the same type may bedistinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

FIG. 1 illustrates an example of a wireless communications system forphysical uplink control channel (PUCCH) with machine type communication(MTC) devices in accordance with various aspects of the presentdisclosure;

FIG. 2 illustrates an example of a wireless communications subsystem forPUCCH with MTC devices in accordance with various aspects of the presentdisclosure;

FIG. 3 illustrates an example of a resource offset configuration forPUCCH with MTC devices in accordance with various aspects of the presentdisclosure;

FIG. 4 illustrates an example of a resource block allocation for PUCCHwith MTC devices in accordance with various aspects of the presentdisclosure;

FIG. 5 illustrates an example of a process flow for PUCCH with MTCdevices in accordance with various aspects of the present disclosure;

FIG. 6 shows a block diagram of a device configured for PUCCH with MTCdevices in accordance with various aspects of the present disclosure;

FIG. 7 shows a block diagram of a device configured for PUCCH with MTCdevices in accordance with various aspects of the present disclosure;

FIG. 8 shows a block diagram of a PUCCH module configured for PUCCH withMTC devices in accordance with various aspects of the presentdisclosure;

FIG. 9 illustrates a block diagram of a system including a deviceconfigured for PUCCH with MTC devices in accordance with various aspectsof the present disclosure;

FIG. 10 illustrates a block diagram of a system including a base stationconfigured for PUCCH with MTC devices in accordance with various aspectsof the present disclosure;

FIG. 11 shows a flowchart illustrating a method for PUCCH with MTCdevices in accordance with various aspects of the present disclosure;

FIG. 12 shows a flowchart illustrating a method for PUCCH with MTCdevices in accordance with various aspects of the present disclosure;

FIG. 13 shows a flowchart illustrating a method for PUCCH with MTCdevices in accordance with various aspects of the present disclosure;

FIG. 14 shows a flowchart illustrating a method for PUCCH with MTCdevices in accordance with various aspects of the present disclosure;

FIG. 15 shows a flowchart illustrating a method for PUCCH with MTCdevices in accordance with various aspects of the present disclosure;and

FIG. 16 shows a flowchart illustrating a method for PUCCH with MTCdevices in accordance with various aspects of the present disclosure.

DETAILED DESCRIPTION

The described features generally relate to improved systems, methods, orapparatuses for a physical uplink (UL) control channel (PUCCH) withMachine Type Communication (MTC) devices. Some wireless systems mayprovide for automated communication such as MTC or Machine-to-Machine(M2M) communication. M2M or MTC may refer to technologies thatcommunicate without human intervention. In some cases, MTC devices mayhave limited capabilities. For example, while some MTC devices may havebroadband capacity, other MTC devices may be limited to narrowbandcommunications. This narrowband limitation may, for example, interferewith the ability of an MTC device to receive control channel informationusing the full bandwidth served by a base station. In some wirelesscommunication systems, such as Long Term Evolution (LTE), an MTC devicehaving limited bandwidth capability (or another device with similarcapabilities) may be referred to as a category 0 device.

In some cases, MTC devices may have reduced peak data rates (e.g., amaximum transport block size may be 1000 bits). Additionally, an MTCdevice may have rank 1 transmission and one antenna for receiving. Thismay limit an MTC device to half-duplex communication (i.e., the devicemay not be capable of simultaneously transmitting and receiving). If anMTC device is half-duplex, it may have relaxed switching time (e.g.,from transmission (Tx) to reception (Rx) or vice versa). For example, anominal switching time for a non-MTC device may be 20 μs while aswitching time for an MTC device may be 1 ms. MTC enhancements (eMTC) ina wireless system may allow narrowband MTC devices to effectivelyoperate within wider system bandwidth operations (e.g., 1.4/3/5/10/15/20MHz). For example, an MTC device may support 1.4 MHz bandwidth (i.e., 6resources blocks). In some instances, coverage enhancements of such MTCdevices may be achieved by power boosting of (e.g., of up to 15 dB).

MTC devices may be subject to different degrees of coverage enhancementsbased on various factors including traffic type, location, andinterference. For instance, some MTC devices may find that using littleto no coverage enhancements is sufficient for their applications and/orcommunication environment. However, other MTC devices within the samecoverage area may find the same level of coverage enhancementsinsufficient. Thus, a base station such as an evolved node B (eNB) mayprovide and handle different levels of coverage enhancements fordifferent MTC devices, which may introduce resource management issuesand place a processing/scheduling burden on the system.

For MTC devices without coverage enhancements, an eNB may use implicitphysical UL control channel (PUCCH) resource allocation. However, theremay be more control channel elements (CCEs) than resource blocks (RBs),which may create an unnecessarily large number of PUCCH resources (e.g.,if the implicit resource allocation is based on a starting CCE). Thus,the resource allocation may be based on physical downlink shared controlchannel (PDSCH) resources instead of PDCCH resource (e.g., the startingRB of PDSCH may be used to derive the PUCCH resource foracknowledgement/negative acknowledgement (ACK/NACK) feedback). Ifmultiple antenna configurations are not supported, there may be up to 61-RB PDSCH assignments for MTC devices (i.e., up to 6 implicit PUCCHresources). In such cases, the MTC devices may use mirror hopping ofPUCCH over slots, which may improve frequency diversity gain.

For MTC devices with coverage enhancements, PUCCH resource allocationmay be done implicitly or explicitly. If the resource allocation is doneimplicitly, an eNB may allocate resources separately for MTC deviceswith different levels of coverage enhancements. For instance, an eNB mayapply different resource starting offsets to different MTC devices,according the coverage of the MTC devices (e.g., an MTC device withoutcoverage enhancements may be configured with a first PUCCH resourcestarting offset; an MTC device with low coverage enhancements may beconfigured with a second PUCCH resource offset; an MTC device withmedium coverage enhancements may be configured with a third PUCCHresource offset; and an MTC device with large coverage enhancements maybe configured with a fourth PUCCH resource offset).

The implicit resource allocation may be based on a PDCCH resource or aPDSCH resource (e.g., the PDCCH resource in the first or the lastsubframe in a PDCCH bundle; or the PDSCH resource in the first or thelast subframe in a PDSCH bundle). For explicit resource allocation, anMTC device may be configured with explicit resources for transmissionsunder coverage enhancements. The configuration may be done separatelyfor different MTC devices, according to the different coverageenhancement levels of the MTC devices. The configuration may also bedone separately for different coverage enhancement levels of a singleMTC device if the MTC device is configured with more than one coverageenhancement level. The number of explicit resources for a given coverageenhancement level may be one or more. If more than one resource isconfigured, a control channel may indicate to an MTC device whichresource to use.

The following description provides examples, and is not limiting of thescope, applicability, or examples set forth in the claims. Changes maybe made in the function and arrangement of elements discussed withoutdeparting from the scope of the disclosure. Various examples may omit,substitute, or add various procedures or components as appropriate. Forinstance, the methods described may be performed in an order differentfrom that described, and various steps may be added, omitted, orcombined. Also, features described with respect to some examples may becombined in other examples.

FIG. 1 illustrates an example of a wireless communications system 100 inaccordance with various aspects of the present disclosure. The wirelesscommunications system 100 includes base stations 105, at least one userequipment (UE) 115, and a core network 130. The core network 130 mayprovide user authentication, access authorization, tracking, interneprotocol (IP) connectivity, and other access, routing, or mobilityfunctions. The base stations 105 interface with the core network 130through backhaul links 132 (e.g., S1, etc.). The base stations 105 mayperform radio configuration and scheduling for communication with theUEs 115, or may operate under the control of a base station controller(not shown). In various examples, the base stations 105 may communicate,either directly or indirectly (e.g., through core network 130), with oneanother over backhaul links 134 (e.g., X1, etc.), which may be wired orwireless communication links.

The base stations 105 may wirelessly communicate with the UEs 115 viaone or more base station antennas. Each of the base stations 105 mayprovide communication coverage for a respective geographic coverage area110. In some examples, base stations 105 may be referred to as a basetransceiver station, a radio base station, an access point, a radiotransceiver, a NodeB, eNodeB (eNB), Home NodeB, a Home eNodeB, or someother suitable terminology. The geographic coverage area 110 for a basestation 105 may be divided into sectors making up only a portion of thecoverage area (not shown). The wireless communications system 100 mayinclude base stations 105 of different types (e.g., macro or small cellbase stations). There may be overlapping geographic coverage areas 110for different technologies

In some examples, the wireless communications system 100 is a Long TermEvolution (LTE)/LTE-Advanced (LTE-A) network. In LTE/LTE-A networks, theterm evolved node B (eNB) may be generally used to describe the basestations 105, while the term UE may be generally used to describe theUEs 115. The wireless communications system 100 may be a heterogeneousLTE/LTE-A network in which different types of eNBs provide coverage forvarious geographical regions. For example, each eNB or base station 105may provide communication coverage for a macro cell, a small cell, orother type of cell. The term “cell” is a 3GPP term that can be used todescribe a base station, a carrier or component carrier associated witha base station, or a coverage area (e.g., sector, etc.) of a carrier orbase station, depending on context.

A macro cell generally covers a relatively large geographic area (e.g.,several kilometers in radius) and may allow unrestricted access by UEs115 with service subscriptions with the network provider. A small cellis a lower-powered base station, as compared with a macro cell, that mayoperate in the same or different (e.g., licensed, unlicensed, etc.)frequency bands as macro cells. Small cells may include pico cells,femto cells, and micro cells according to various examples. A pico cell,for example, may cover a small geographic area and may allowunrestricted access by UEs 115 with service subscriptions with thenetwork provider. A femto cell may also cover a small geographic area(e.g., a home) and may provide restricted access by UEs 115 having anassociation with the femto cell (e.g., UEs 115 in a closed subscribergroup (CSG), UEs 115 for users in the home, and the like). An eNB for amacro cell may be referred to as a macro eNB. An eNB for a small cellmay be referred to as a small cell eNB, a pico eNB, a femto eNB, or ahome eNB. An eNB may support one or multiple (e.g., two, three, four,and the like) cells (e.g., component carriers).

The wireless communications system 100 may support synchronous orasynchronous operation. For synchronous operation, the base stations 105may have similar frame timing, and transmissions from different basestations 105 may be approximately aligned in time. For asynchronousoperation, the base stations 105 may have different frame timing, andtransmissions from different base stations 105 may not be aligned intime. The techniques described herein may be used for either synchronousor asynchronous operations.

The communication networks that may accommodate some of the variousdisclosed examples may be packet-based networks that operate accordingto a layered protocol stack and data in the user plane may be based onthe IP. A radio link control (RLC) layer may perform packet segmentationand reassembly to communicate over logical channels. A medium accesscontrol (MAC) layer may perform priority handling and multiplexing oflogical channels into transport channels. The MAC layer may also usehybrid automatic repeat request (HARM) to provide retransmission at theMAC layer to improve link efficiency. In the control plane, the radioresource control (RRC) protocol layer may provide establishment,configuration, and maintenance of an RRC connection between a UE 115 andthe base stations 105. The RRC protocol layer may also be used for corenetwork 130 support of radio bearers for the user plane data. At thephysical (PHY) layer, the transport channels may be mapped to physicalchannels.

The UEs 115 may be dispersed throughout the wireless communicationssystem 100, and each UE 115 may be stationary or mobile. A UE 115 mayalso include or be referred to by those skilled in the art as a mobilestation, a subscriber station, a mobile unit, a subscriber unit, awireless unit, a remote unit, a mobile device, a wireless device, awireless communications device, a remote device, a mobile subscriberstation, an access terminal, a mobile terminal, a wireless terminal, aremote terminal, a handset, a user agent, a mobile client, a client, orsome other suitable terminology. A UE 115 may be a cellular phone, apersonal digital assistant (PDA), a wireless modem, a wirelesscommunication device, a handheld device, a tablet computer, a laptopcomputer, a cordless phone, a wireless local loop (WLL) station, or thelike. A UE may be able to communicate with various types of basestations and network equipment including macro eNBs, small cell eNBs,relay base stations, and the like.

Some types of wireless devices may provide for automated communication.Automated wireless devices may include those implementing MTC or M2Mcommunication. M2M or MTC may refer to data communication technologiesthat allow devices to communicate with one another or a base stationwithout human intervention. For example, M2M or MTC may refer tocommunications from devices that integrate sensors or meters to measureor capture information and relay that information to a central server orapplication program that can make use of the information or present theinformation to humans interacting with the program or application. SomeUEs 115 may be MTC devices, such as those designed to collectinformation or enable automated behavior of machines. Examples ofapplications for MTC devices include smart metering, inventorymonitoring, water level monitoring, equipment monitoring, healthcaremonitoring, wildlife monitoring, weather and geological eventmonitoring, fleet management and tracking, remote security sensing,physical access control, and transaction-based business charging. An MTCdevice may operate using half-duplex (one-way) communications at areduced peak rate. MTC devices may also be configured to enter a powersaving “deep sleep” mode when not engaging in active communications. Insome cases, MTC devices may be configured for regular transmissionintervals that alternate with sleep intervals.

The communication links 125 shown in wireless communications system 100may include uplink UL transmissions from a UE 115 to a base station 105,or downlink (DL) transmissions, from a base station 105 to a UE 115. Thedownlink transmissions may also be called forward link transmissionswhile the UL transmissions may also be called reverse linktransmissions. Each communication link 125 may include one or morecarriers, where each carrier may be a signal made up of multiplesub-carriers (e.g., waveform signals of different frequencies) modulatedaccording to the various radio technologies described above. Eachmodulated signal may be sent on a different sub-carrier and may carrycontrol information (e.g., reference signals, control channels, etc.),overhead information, user data, etc. The communication links 125 maytransmit bidirectional communications using frequency division duplex(FDD) (e.g., using paired spectrum resources) or time division duplex(TDD) operation (e.g., using unpaired spectrum resources). Framestructures may be defined for FDD (e.g., frame structure type 1) and TDD(e.g., frame structure type 2).

In some embodiments of the wireless communications system 100, basestations 105 or UEs 115 may include multiple antennas for employingantenna diversity schemes to improve communication quality andreliability between base stations 105 and UEs 115. Additionally oralternatively, base stations 105 or UEs 115 may employ multiple inputmultiple output (MIMO) techniques that may take advantage of multi-pathenvironments to transmit multiple spatial layers carrying the same ordifferent coded data.

Wireless communications system 100 may support operation on multiplecells or carriers, a feature which may be referred to as carrieraggregation (CA) or multi-carrier operation. A carrier may also bereferred to as a component carrier (CC), a layer, a channel, etc. Theterms “carrier,” “component carrier,” “cell,” and “channel” may be usedinterchangeably herein. A UE 115 may be configured with multipledownlink CCs and one or more UL CCs for carrier aggregation. Carrieraggregation may be used with both FDD and TDD component carriers.

LTE systems may utilize orthogonal frequency division multiple access(OFDMA) on the DL and single carrier frequency division multiple access(SC-FDMA) on the UL. OFDMA and SC-FDMA partition the system bandwidthinto multiple (K) orthogonal subcarriers, which are also commonlyreferred to as tones or bins. Each subcarrier may be modulated withdata. The spacing between adjacent subcarriers may be fixed, and thetotal number of subcarriers (K) may be dependent on the systembandwidth. For example, K may be equal to 72, 180, 300, 600, 900, or1200 with a subcarrier spacing of 15 kilohertz (KHz) for a correspondingsystem bandwidth (with guardband) of 1.4, 3, 5, 10, 15, or 20 megahertz(MHz), respectively. The system bandwidth may also be partitioned intosub-bands. For example, a sub-band may cover 1.08 MHz, and there may be1, 2, 4, 8 or 16 sub-bands.

Time intervals in LTE may be expressed in multiples of a basic time unit(e.g., the sampling period, Ts=1/30,720,000 seconds). Time resources maybe organized according to radio frames of length of 10 ms(Tf=307200·Ts), which may be identified by a system frame number (SFN)ranging from 0 to 1023. Each frame may include ten 1 ms subframesnumbered from 0 to 9. A subframe may be further divided into two 0.5 msslots, each of which contains 6 or 7 modulation symbol periods(depending on the length of the cyclic prefix prepended to each symbol).Excluding the cyclic prefix, each symbol contains 2048 sample periods.In some cases the subframe may be the smallest scheduling unit, alsoknown as a transmission time interval (TTI). In other cases, a TTI maybe shorter than a subframe or may be dynamically selected (e.g., inshort TTI bursts or in selected component carriers using short TTIs).

A resource element may consist of one symbol period and one subcarrier(a 15 KHz frequency range). A resource block may contain 12 consecutivesubcarriers in the frequency domain and, for a normal cyclic prefix ineach OFDM symbol, 7 consecutive OFDM symbols in the time domain (1slot), or 84 resource elements. Some resource elements may include DLreference signals (DL-RS). The DL-RS may include a cell-specificreference signals (CRS) and a UE-specific RS (UE-RS). UE-RS may betransmitted on the resource blocks associated with PDSCH. The number ofbits carried by each resource element may depend on the modulationscheme (the configuration of symbols that may be selected during eachsymbol period). Thus, the more resource blocks that a UE receives andthe higher the modulation scheme, the higher the data rate may be forthe UE.

Data may be divided into logical channels, transport channels, andphysical layer channels. Channels may also be classified into ControlChannels and Traffic Channels. Logical control channels may includepaging control channel (PCCH) for paging information, broadcast controlchannel (BCCH) for broadcast system control information, multicastcontrol channel (MCCH) for transmitting multimedia broadcast multicastservice (MBMS) scheduling and control information, dedicated controlchannel (DCCH) for transmitting dedicated control information, commoncontrol channel (CCCH) for random access information, DTCH for dedicatedUE data, and multicast traffic channel (MTCH), for multicast data. DLtransport channels may include broadcast channel (BCH) for broadcastinformation, a downlink shared channel (DL-SCH) for data transfer,paging channel (PCH) for paging information, and multicast channel (MCH)for multicast transmissions. UL transport channels may include randomaccess channel (RACH) for access and UL shared channel (UL-SCH) fordata. DL physical channels may include physical broadcast channel (PBCH)for broadcast information, physical control format indicator channel(PCFICH) for control format information, physical downlink controlchannel (PDCCH) for control and scheduling information, physical HARQindicator channel (PHICH) for HARQ status messages, physical downlinkshared channel (PDSCH) for user data and physical multicast channel(PMCH) for multicast data. UL physical channels may include physicalrandom access channel (PRACH) for access messages, PUCCH for controldata, and physical UL shared channel (PUSCH) for user data.

PUCCH may be mapped to a control channel defined by a code and twoconsecutive resource blocks. UL control signaling may depend on thepresence of timing synchronization for a cell. PUCCH resources forscheduling request (SR) and channel quality indicator (CQI) reportingmay be assigned (and revoked) through RRC signaling. In some cases,resources for SR may be assigned after acquiring synchronization througha RACH procedure. In other cases, an SR may not be assigned to a UE 115through the RACH (i.e., synchronized UEs 115 may or may not have adedicated SR channel). PUCCH resources for SR and CQI may be lost whenthe UE is no longer synchronized.

HARQ transmissions (e.g., on PUCCH) may be a method of ensuring thatdata is received correctly over a wireless communication link 125. HARQmay include a combination of error detection (e.g., using a cyclicredundancy check (CRC)), forward error correction (FEC), andretransmission (e.g., automatic repeat request (ARQ)). HARQ may improvethroughput at the MAC layer in poor radio conditions (e.g.,signal-to-noise conditions). In Incremental Redundancy HARQ, incorrectlyreceived data may be stored in a buffer and combined with subsequenttransmissions to improve the overall likelihood of successfully decodingthe data. In some cases, redundancy bits are added to each message priorto transmission. This may be especially useful in poor conditions. Inother cases, redundancy bits are not added to each transmission, but areretransmitted after the transmitter of the original message receives anegative acknowledgement (NACK) indicating a failed attempt to decodethe information.

In some cases a TTI (e.g., 1 ms in LTE, the equivalent of one subframe)may be defined as the smallest unit of time in which a base station 105may schedule a UE 115 for UL or DL transmission. For example, if a UE115 is receiving DL data, then during each 1 ms interval a base station105 may assign resources and indicate (via PDCCH transmissions) to theUE 115 where to look for its DL data. If a transmission is unsuccessful,a UE 115 (or a base station 105) may respond with a NACK in accordancewith a HARQ procedure. In some cases, HARQ procedures may result inmultiple retransmissions of data, which may result in delays and animpaired user experience. The degradation in service may be particularlysignificant in poor radio conditions (e.g., near the edge of a cell).The degradation may not be acceptable for certain time-sensitive userservices such as voice over internet protocol (VoIP) (or voice over LongTerm evolution (VoLTE)). TTI bundling may be used to improve a wirelesscommunication link 125 in such radio conditions. TTI bundling mayinvolve sending multiple copies of the same information in a group ofconsecutive or non-consecutive subframes (TTIs) rather than waiting fora NACK before retransmitting redundancy versions as in typical HARQoperation.

According to the present disclosure, a wireless device such as a UE 115may be configured with a transmission time interval (TTI) bundlingparameter. The device may then identify one or more resources for PUCCHbased on the TTI bundling parameter (e.g., using either an implicit oran explicit indication from another wireless node such as a serving cellof a base station 105) and transmit the PUCCH using the identifiedresources. The device may also identify a DCI format based on the TTIbundling parameter. For example, a resource allocation granularity levelmay be associated with the bundling parameter, and the length of a DCIfield may depend on the resource allocation granularity level.

FIG. 2 illustrates an example of a wireless communications subsystem 200for PUCCH with MTC devices in accordance with various aspects of thepresent disclosure. Wireless communications subsystem 200 may include UE115-a and UE 115-b, which may be examples of a UE 115 described withreference to FIG. 1. In some examples, one or more of the UEs 115 may bean MTC device. For example, as illustrated, UE 115-b may be an MTCdevice. Wireless communications subsystem 200 may also include basestation 105-a, which may be an example of a base station 105 describedabove with reference to FIG. 1. Base station 105-a may transmit controland data to any UE 115 within its coverage area 110-a via acommunication link 125. For example, communication link 125-a may allowfor bidirectional communication between a UE 115-a and a base station105-a, while communication link 125-b may provide for communicationbetween UE 115-b and base station 105-a.

Wireless communications subsystem 200 may employ a hybrid automaticrepeat request (HARQ) feedback scheme to notify a transmitting entity(e.g., base station 105-a) of the reception status of transmittedsubframes. Wireless communications subsystem 200 may also use coverageenhancements techniques (e.g., power boosting or TTI bundling), whichmay increase the robustness and reliability of communications for one ormore UEs 115.

Wireless communications subsystem 200 may include UEs 115 with differentcapabilities and different communication environments. In some cases, aUE 115 may also be configured with two or more levels of TTI bundling orother coverage enhancements. In such cases, different UEs 115 may usedifferent levels of TTI bundling or other coverage enhancements. Forexample, UE 115-a may be located closer to base station 105-a and mayhave different radio capacity than UE 115-b, which may be an MTC device.UE 115-b may have a longer transmit path than UE 115-a, which mayincrease the level of signal attenuation or interference. Thus, UE 115-bmay use a coverage enhancement level which differs from a coverageenhancement level used by UE 115-a. In some cases, base station 105-amay configure UE 115-b with a different TTI bundling configuration fromUE 115-a (e.g., a higher level of TTI bundling). In some cases resourcesfor PUCCH transmissions may be offset from DL transmissions by a numberof subframes based on the type/level of TTI bundling used by each UE 115(in addition to other factors). This may allow base station 105-a toprevent collisions of PUCCH transmissions (e.g., HARQ feedback) from UE115-a and UE 115-b.

UEs 115 which employ different levels of TTI bundling may also beallocated different granularity levels for resource allocation (e.g.,resources may be allocated for a UE 115 in sets of 1, 3 or 6 RBs). Theallocated RBs may be contiguous in the frequency domain. For example, iftransmissions to UE 115-b are provided in 6 RB segments in the frequencydomain, it may enable the same amount of information to be transmittedin a shorter time period. The duration of a transmission may beinversely correlated to the power consumption. Thus, allocating more RBsspread across the frequency domain may reduce power consumption.Increasing the resource allocation granularity may also enable basestation 105-a (or another wireless device) to reduce the number of bitsfor indicating which RBs are directed to UE 115-b. Thus, in someexamples, different DCI formats may be used for UEs 115 which employdifferent levels of coverage enhancements.

In some cases, PUCCH resource hopping within a subframe and/or acrosssubframes may also be employed. However, the hopped resources may bewithin the same RB within a subframe across subframes to enable coherentchannel estimate (i.e., the resources may be hopped within the same RB,but with different cyclic shifts or spreading codes). As an example,assume a PUCCH has a bundling length of two subframes. The PUCCH may useRB0 in a first slot in the first subframe and RB5 in a second slot of inthe first frame. The PUCCH will still use RB0 in a first lot in thesecond subframe and RB5 in a second slot in the second frame, althoughthe resources in RB0 (or RB5) for the first subframe and the secondsubframe can be different. As another example, assume a PUCCH has abundling length of two subframes. The PUCCH may use RB0 in a first slotin the first subframe and RB0 in a second slot of in the first frame,although the resources in RB0 can be different in the first slot and inthe second slot. The PUCCH will still use RB0 in a first slot in thesecond subframe and RB0 in a second slot in the second frame, althoughthe resources in RB0 for the first subframe and the second subframe canbe different. Similarly, resource hopping may be enabled for otherchannels, such as PDSCH, PUSCH, etc. For an UE 115, such as an MTCdevice, which uses PUCCH mirror hopping and one RB for PUCCH, theremaining resources may be used by the PUSCH (i.e., the remaining 5 RBsfrom the central 6 RBs of the carrier bandwidth in the case that thedevice monitors on those RBs). For example, if one RB is designated forPUCCH mirror hopping, and if PUSCH is allocated on the RB, the PUSCH mayrate match around the PUCCH.

FIG. 3 illustrates an example of resource offset configuration 300 inaccordance with various aspects of the present disclosure. Resourceoffset configuration 300 may be used by a UE 115 and a base station 105as described with reference to FIGS. 1-2. Resource offset configuration300 may include transmission of DL control TTI bundles 305, DL data TTIbundles 310, and PUCCH bundles 315, which may be scheduled to prevent oralleviate collision of PUCCH transmissions from different UEs 115.

Resource offset configuration 300 may include a DL control TTI bundle305-a from a wireless node such as a base station 105 to a first UE 115(not shown). DL control TTI bundle 305-a may include fifteen versions ofthe same subframe (i.e., DL control TTI bundle 305-a may be atransmission with a first level of TTI bundling), which may conveycontrol information for the first UE 115. Immediately subsequent to thetransmission of DL control TTI bundle 305-a, the base station 105 maytransmit DL data TTI bundle 310-a. DL data TTI 310-a may use the sameTTI bundling level as DL control TTI bundle 305-a, and may includeredundant versions of a subframe carrying data for the first UE 115. Thefirst UE 115 may receive DL data TTI 310-a and transmit a PUCCH bundle315-a according to resource offset 320-a. Resource offset 320-a may bebased on the TTI bundling of the first UE 115 or on other factors suchas the resource offset of other UEs 115 scheduled by the same node.

Resource offset configuration 300 may include a DL control TTI bundle305-b from the wireless node to a second UE 115 (not shown). DL controlTTI bundle 305-b may use a different level of TTI bundling than DLcontrol TTI bundle 305-b (e.g., DL control TTI bundle 305-b may include4 redundant versions of a same subframe). Following DL control TTIbundle 305-b, the base station 105 may transmit DL data TTI bundle310-b, which may correspond to DL control TTI bundle 305-b and thus usethe same TTI bundling. The second UE 115 may receive DL data TTI bundle310-b and send a PUCCH bundle 315-b which corresponds to DL data TTIbundle 310-b and which is transmitted according to resource offset320-b. Resource offset 320-b may be based at least in part on the TTIbundling for the second UE 115. PUCCH bundle 315-b may use the same TTIbundling as DL control TTI bundle 305-b and DL data TTI bundle 310-b.However, in some examples the TTI bundling levels of the DL control TTIbundles 305, the DL data TTI bundles 310, and the PUCCH bundles 315 maybe different.

Resource offset configuration 300 may also include communicationsbetween the wireless node and a third UE 115 (not shown). The third UE115 may not use TTI bundling. Thus, DL control TTI bundle 305-c mayinclude a single version of a subframe conveying control information.Accordingly, DL data TTI bundle 310-c may include a single version of asubframe conveying data. The third UE 115 may receive DL data TTI bundle310-c and transmit PUCCH bundle 315-c in response. PUCCH bundle 315-cmay be transmitted according to resource offset 320-c, which may bebased on the TTI bundling for the third UE 115. Thus, the resourceoffsets 320 may be different for different UEs 115, and may be based onthe coverage enhancements of the UEs 115.

The TTI bundling levels and resource offsets depicted in resource offsetconfiguration 300 are examples of TTI bundling levels and resourceoffsets, but other configurations are also possible. Also, in some casesa wireless node may aggregate transmissions to groups of UEs 115 ineither the time domain or the frequency domain. For example, a basestation 105 may select a subset of the RBs available in the frequencydomain for use by UEs 115 with one level of TTI bundling (and oneresource offset) while dedicating another frequency region for use byanother group of UEs 115 with a different TTI bundling level and, insome cases, a different resource offset. In another example, a wirelessnode may dedicate different time periods to transmissions to and fromUEs 115 with a certain level of TTI bundling. In some cases, a single UE115 may also be configured to use more than one level of TTI bundling ormore than one resource offset.

FIG. 4 illustrates an example of resource block allocation 400 for PUCCHwith MTC devices in accordance with various aspects of the presentdisclosure. Resource block allocation 400 may be used by a wirelessdevice such as a UE 115 or a base station 105 described with referenceto FIG. 1. For example, a base station 105 may allocate a number ofresource blocks for use by a particular UE 115. The resource allocationmay be done according to a predetermined or dynamic granularity (i.e., aminimum number of RBs assigned to a particular UE 115 during any givenTTI). Although resource block allocation 400 is shown in terms of 3 RBgranularity, the granularity of the allocation may be some other numberof RBs (e.g., 1, 2, or 6).

Resource block allocation 400 may include four variations of an exampleresource group 405 which may include 6 RBs arranged contiguously in thefrequency domain. Resource groups 405 may represent the middle six RBsof a carrier bandwidth. That is, in some cases, a UE 115 such as an MTCdevice may be configured to receive only resource group 405 from the RBsavailable in a cell. For a resource allocation granularity of 3 RBs,there may be four possible combinations of RB allocation (i.e., theallocation may be represented by 2 bits). In one example, RB set 410-aof resource group 405-a may be allocated for use by a UE 115. In analternative option, the RB set 410-b of resource group 405-b may beallocated for the UE 115. Or, RB set 410-c of resource group 405-c maybe allocated for use by the UE 115. An additional allocation option maybe depicted by resource group 405-d, in which RB set 410-d is allocatedfor use by the UE 115. As another example, for a resource allocationgranularity of 3 RBs, there may be three possible combinations of RBallocation (i.e., the allocation may be represented by 2 bits). Thefirst combination can be depicted by RB set 410-a, the secondcombination can be depicted by resource group 405-d, while the thirdcombination is the entire 6 RBs. In this example, the starting offsetfor a resource allocation is also a function of the resource allocationgranularity. That is, a resource allocation can only start from RB 0 orRB 3. As another example, if an MTC device uses 2 RB allocation (notshown), there may be 5 possible combinations of resource allocation(i.e., 3 bits may be used to convey the resource allocation). As anexample, the first combination can be the first 2 RBs, the secondcombination can be the second 2 RBs, the third combination can be thethird 2 RBs, the fourth combination can be the first 4 RBs, while thefifth combination can be the entire 6 RBs. With 1 RB granularity, 5 bitsmay be used to convey the resource information.

Thus, resource allocation may be done according to various levels ofgranularity, which may correspond to the respective TTI bundling levelsof the MTC devices. For example, an MTC device with a high TTI bundlinglevel may use more resources in a subframe for the control/data channel.Thus, the transmission time may be reduced, which may reduce powerconsumption. In other words, MTC devices with higher TTI bundling levelsmay use coarser resource granularity than MTC devices with low TTIbundling levels (e.g., an MTC device without coverage enhancements mayuse a resource granularity of a single RB while an MTC device with highlevels of coverage enhancements may use a resource granularity of 3 RBsor 6 RBs). If an MTC device uses 6 RB allocation, the scheduling node(e.g., the base station 105) may refrain from indicating the resourceallocation in PDCCH, which may reduce the overall number of bits used toconvey resource allocation. Additionally, such a scheme may allow asingle PUCCH resource to convey the information.

In some examples, MTC devices with different TTI bundling levels mayhave different DCI formats, which may be due to different resourcesallocations granularity or different modulation coding scheme (MCS)sets. As an example, for a TTI bundling level of one (i.e., no TTIbundling), a 5-bit MCS information field may be used, which may indicatedifferent combinations of modulation and coding schemes. The modulationmay include QPSK, 16 QAM, etc. The corresponding transport block sizemay be determined based at least in part on the MCS information field.For a TTI bundling level of larger than one, a 2-bit MCS informationfield may be used, which may indicate a different set of modulation andcoding schemes. The modulation may be limited to QPSK only. Accordingly,a transport block size may also be determined based at least in part onthe 2-bit MCS. In such cases, a smaller control size for MTC devices mayimprove coverage. In an alternative example, MTC devices with differentcoverage levels may be placed in different frequency or time locations.For instance, in a 5 MHz system there may be 4 blocks, each of 6 RBs.Each block may be dedicated to a specific set of MTC devices with thesame coverage level. In another examples, a block of 6 RBs may be usedfor a set of MTC devices with a first coverage level, and then laterused for a different set of MTC devices with a second coverage level.

In some cases, UEs 115 without coverage enhancements may use 1 RBallocation granularity, and UEs 115 such as MTC devices with coverageenhancements may use 3 RB resource allocation. In some cases there maybe multiple levels of coverage enhancements (e.g., three levelsassociated with three levels of TTI bundling). Thus, the total number ofPUCCH resources used for hybrid automatic repeat request (HARM) resourcesignaling may depend on the number of blocks or the resource allocationgranularity within each block.

In some cases, the granularity of the resource allocation may be basedat least in part on the TTI bundling level of a UE 115. For example, UEs115 with higher TTI bundling levels may be allocated resources accordingto coarser granularity than UEs 115 without coverage enhancements. Forexample, a high TTI bundling level UE 115 may use 6 RB allocation whilea UE 115 without coverage enhancement may use single RB allocation. Thegranularity of resource allocation may affect the number of resourcesused for PUCCH (e.g., coarser resource allocation may reduce the amountof PUCCH resources used to convey assignments). For instance, when 3 RBgranularity is used, a base station 105 may use two PUCCH resources.

FIG. 5 illustrates an example of a process flow 500 for PUCCH with MTCdevices in accordance with various aspects of the present disclosure.Process flow 500 may include a UE 115-c, which may be an example of a UE115 described above with reference to FIGS. 1-2. In some cases, UE 115-cmay be an MTC device. Process flow 500 may also include a base station105-b, which may be an example of a base station 105 described abovewith reference to FIGS. 1-2.

At step 505, UE 115-c may identify a TTI bundling parameter. Forexample, base station 105-b may transmit a configuration messageincluding the TTI bundling parameter. The configuration may also include(implicitly or explicitly) a resource offset for PUCCH transmissions.

At step 510, UE 115-c may identify a resource offset for PUCCHtransmissions based on the TTI bundling parameter or the indication frombase station 105-b.

At step 515, base station may transmit DL control information and datato UE 115-c. At step 520, UE 115-c may identify one or more resourcesfor an UL control channel based at least in part on the TTI bundlingparameter (and a resource index of the DL control or data transmission).In some examples identifying the one or more resources is based on animplicit resource allocation. In some examples the implicit resourceallocation is based at least in part on a PDCCH (control) resource or aPDSCH (data) resource.

In some examples identifying the one or more resources is based at leastin part on a correspondence between a set of frequency ranges of acarrier bandwidth of a serving cell and a set of TTI bundlingparameters, wherein the set of TTI bundling parameters comprises the TTIbundling parameter of the UL control channel. In some cases, UE 115-cmay determine a correspondence between a set of resource offsets and aset of TTI bundling parameters, wherein the set of TTI bundlingparameters comprises the TTI bundling parameter of the UL controlchannel. In some examples identifying the one or more resources includesselecting a resource offset from the set of resource offsets based atleast in part on the TTI bundling parameter and the correspondence.

At step 525, UE 115-c may transmit the UL control channel using the oneor more resources. For example, UE 115-c may transmit an ACK or NACKindicating whether the DL data was successfully received at step 515.Base station 105-b may receive the UL control channel using the sameresources.

In some cases UE 115-c may also identify a DCI format based at least inpart on the TTI bundling parameter. In some examples the TTI bundlingparameter corresponds to a resource allocation granularity level. Insome examples the resource allocation granularity level is based on aminimum of a plurality of RBs, such that a DCI field indicating a set ofresources for an UL control channel includes a number bits based on theresource allocation granularity level. In some examples the TTI bundlingparameter corresponds to a modulation and coding scheme (MCS)information field, and the DCI format is based on the MCS informationfield.

As an example, UE 115-c may determine a first TTI bundling length, andthen determine a first length of the MCS information field based on thefirst TTI bundling length.

The UE 115-c may then determine a second TTI bundling length, where thesecond TTI bundling length may be larger than the first TTI bundlinglength. UE 115-c may then determine a second length of the MCSinformation field based on the second TTI bundling length, where thesecond length of the MCS information field is smaller than the firstlength of the MCS information field.

FIG. 6 shows a block diagram of a wireless device 600 configured forPUCCH with MTC devices in accordance with various aspects of the presentdisclosure. Wireless device 600 may be an example of aspects of a UE 115or a base station 105 described with reference to FIGS. 1-5. Wirelessdevice 600 may include a receiver 605, a PUCCH module 610, or atransmitter 615. Wireless device 600 may also include a processor. Eachof these components may be in communication with each other.

The components of wireless device 600 may, individually or collectively,be implemented with at least one application specific integrated circuit(ASIC) adapted to perform some or all of the applicable functions inhardware. Alternatively, the functions may be performed by one or moreother processing units (or cores), on at least one IC. In otherembodiments, other types of integrated circuits may be used (e.g.,Structured/Platform ASICs, a field programmable gate array (FPGA), oranother semi-custom IC), which may be programmed in any manner known inthe art. The functions of each unit may also be implemented, in whole orin part, with instructions embodied in a memory, formatted to beexecuted by one or more general or application-specific processors.

The receiver 605 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to PUCCH forMTC devices, etc.). Information may be passed on to the PUCCH module610, and to other components of wireless device 600. In some examples,the receiver 605 may receive the UL control channel using the one ormore resources (e.g., a base station 105 may receive PUCCH). In someexamples, the receiver 605 may receive a configuration of a plurality ofresources for the TTI bundling parameter (e.g., a UE 115 may receive theconfiguration in a DL control channel). In some examples, the receiver605 may receive a resource indication in a DL control channel. In someexamples, the receiver 605 may receive a DL control channel based atleast in part on the DCI format.

The PUCCH module 610 may identify a TTI bundling parameter of an ULcontrol channel, and identify one or more resources for an UL controlchannel based at least in part on the TTI bundling parameter. In someexamples, identifying the one or more resources comprises receiving anindication of the one or more resources from a wireless node.

The transmitter 615 may transmit signals received from other componentsof wireless device 600. In some embodiments, the transmitter 615 may becollocated with the receiver 605 in a transceiver module. Thetransmitter 615 may include a single antenna, or it may include aplurality of antennas. In some examples, the transmitter 615 maytransmit the UL control channel using the one or more resources (e.g., aUE 115 may transmit PUCCH). In some examples, the transmitter 615 maytransmit a DL control channel based at least in part on the DCI format(e.g., a base station 105 may transmit PDCCH).

FIG. 7 shows a block diagram of a wireless device 700 for PUCCH with MTCdevices in accordance with various aspects of the present disclosure.Wireless device 700 may be an example of aspects of a wireless device600 described with reference to FIGS. 1-6 (e.g., it may represent a UE115 or a base station 105). Wireless device 700 may include a receiver605-a, a PUCCH module 610-a, or a transmitter 615-a. Wireless device 700may also include a processor. Each of these components may be incommunication with each other. The PUCCH module 610-a may also include abundling parameter module 705, and a UL control resource module 710.

The components of wireless device 700 may, individually or collectively,be implemented with at least one ASIC adapted to perform some or all ofthe applicable functions in hardware. Alternatively, the functions maybe performed by one or more other processing units (or cores), on atleast one IC. In other embodiments, other types of integrated circuitsmay be used (e.g., Structured/Platform ASICs, an FPGA, or anothersemi-custom IC), which may be programmed in any manner known in the art.The functions of each unit may also be implemented, in whole or in part,with instructions embodied in a memory, formatted to be executed by oneor more general or application-specific processors.

The receiver 605-a may receive information which may be passed on toPUCCH module 610-a, and to other components of wireless device 700. ThePUCCH module 610-a may perform the operations described above withreference to FIG. 6. The transmitter 615-a may transmit signals receivedfrom other components of wireless device 700.

The bundling parameter module 705 may identify a TTI bundling parameterof an UL control channel as described above with reference to FIGS. 1-5.In some cases, the bundling parameter module 705 may determine a firstTTI bundling length and a second TTI bundling length, where the secondTTI bundling length is larger than the first TTI bundling length.

The UL control resource module 710 may identify one or more resourcesfor an UL control channel based at least in part on the TTI bundlingparameter as described above with reference to FIGS. 1-5.

FIG. 8 shows a block diagram of a PUCCH module 610-b for PUCCH with MTCdevices in accordance with various aspects of the present disclosure.The PUCCH module 610-b may be an example of aspects of a PUCCH module610 described with reference to FIGS. 6-7. The PUCCH module 610-b mayinclude a bundling parameter module 705-a, and a UL control resourcemodule 710-a. Each of these modules may perform the functions describedabove with reference to FIG. 7. The PUCCH module 610-b may also includean implicit allocation module 805, a frequency range module 810, aresource offset module 815, a resource selection module 820, a hoppingpattern module 825, a DCI format module 830, a resource allocationgranularity module 835, and an MCS information field module 840.

The components of the PUCCH module 610-b may, individually orcollectively, be implemented with at least one ASIC adapted to performsome or all of the applicable functions in hardware. Alternatively, thefunctions may be performed by one or more other processing units (orcores), on at least one IC. In other embodiments, other types ofintegrated circuits may be used (e.g., Structured/Platform ASICs, anFPGA, or another semi-custom IC), which may be programmed in any mannerknown in the art. The functions of each unit may also be implemented, inwhole or in part, with instructions embodied in a memory, formatted tobe executed by one or more general or application-specific processors.

The implicit allocation module 805 may be configured such thatidentifying the one or more resources may include identifying the one ormore resources based on an implicit resource allocation as describedabove with reference to FIGS. 1-5. In some examples, the implicitresource allocation may be based at least in part on a PDCCH resource ora PDSCH resource.

The frequency range module 810 may be configured such that identifyingthe one or more resources may include identifying the one or moreresources based at least in part on a correspondence between a set offrequency ranges of a carrier bandwidth of a serving cell and a set ofTTI bundling parameters, wherein the set of TTI bundling parameters mayinclude the TTI bundling parameter of the UL control channel asdescribed above with reference to FIGS. 1-5.

The resource offset module 815 may determine a correspondence between aset of resource offsets and a set of TTI bundling parameters, whereinthe set of TTI bundling parameters comprises the TTI bundling parameterof the UL control channel as described above with reference to FIGS.1-5. In some examples, identifying the one or more resources comprisesselecting a resource offset from the set of resource offsets based atleast in part on the TTI bundling parameter and the correspondence. Theresource offset module 815 may also receive a configuration indicating aresource offset corresponding to the TTI bundling parameter, whereinidentifying the one or more resources is based on the resource offset.

The resource selection module 820 may identify one resource from theconfigured plurality of resources for the TTI bundling parameter basedon the indication as described above with reference to FIGS. 1-5.

The hopping pattern module 825 may be configured such that identifyingthe one or more resources may include identifying a resource hoppingpattern for a bundled transmission over a plurality of subframes in aresource block as described above with reference to FIGS. 1-5.

The DCI format module 830 may identify a DCI format based at least inpart on the TTI bundling parameter as described above with reference toFIGS. 1-5.

The resource allocation granularity module 835 may be configured suchthat the TTI bundling parameter corresponds to a resource allocationgranularity level, wherein the DCI format may be based at least in parton the resource allocation granularity level as described above withreference to FIGS. 1-5. In some examples, the resource allocationgranularity level may be based on a minimum of a plurality of RBs,wherein a DCI field indicating a set of resources for an UL controlchannel comprises a number bits based on the resource allocationgranularity level. In some examples, the resource allocation granularitylevel may be based on a minimum of 1 RB, wherein a DCI field indicatinga set of resources for an UL control channel comprises a number of bitsbased on the resource allocation granularity level.

The MCS information field module 840 may determine a length of an MCSinformation field based on a TTI bundling length. The MCS informationfield module 840 may be configured such that the TTI bundling parametercorresponds to an MCS information field, wherein the DCI format may bebased at least in part on the MCS information field as described abovewith reference to FIGS. 1-5. The MCS information field module 840 mayalso determine a second length of the MCS information field based on thesecond TTI bundling length, where the second length of the MCSinformation field is smaller than the first length of the MCSinformation field.

FIG. 9 shows a diagram of a system 900 including a UE 115 configured forPUCCH with MTC devices in accordance with various aspects of the presentdisclosure. System 900 may include UE 115-d, which may be an example ofa UE 115, a wireless device 600 or a wireless device 700 described abovewith reference to FIGS. 1-8. UE 115-d may include a PUCCH module 910,which may be an example of a PUCCH module 610 described with referenceto FIGS. 6-8. UE 115-d may also include a coverage enhancement module925. UE 115-d may also include components for bi-directional voice anddata communications including components for transmitting communicationsand components for receiving communications. For example, UE 115-d maycommunicate bi-directionally with UE 115-e or base station 105-c.

The coverage enhancement module 925 may be configured such that the TTIbundling parameter may be based at least in part on a coverageenhancement setting of the device as described above with reference toFIGS. 1-5. In some examples, the device may be an MTC device.

UE 115-d may also include a processor module 905, and memory 915(including software (SW)) 920, a transceiver module 935, and one or moreantenna(s) 940, each of which may communicate, directly or indirectly,with one another (e.g., via buses 945). The transceiver module 935 maycommunicate bi-directionally, via the antenna(s) 940 or wired orwireless links, with one or more networks, as described above. Forexample, the transceiver module 935 may communicate bi-directionallywith a base station 105 or another UE 115. The transceiver module 935may include a modem to modulate the packets and provide the modulatedpackets to the antenna(s) 940 for transmission, and to demodulatepackets received from the antenna(s) 940. While UE 115-d may include asingle antenna 940, UE 115-d may also have multiple antennas 940 capableof concurrently transmitting or receiving multiple wirelesstransmissions.

The memory 915 may include random access memory (RAM) and read onlymemory (ROM). The memory 915 may store computer-readable,computer-executable software/firmware code 920 including instructionsthat, when executed, cause the processor module 905 to perform variousfunctions described herein (e.g., PUCCH for MTC devices, etc.).Alternatively, the software/firmware code 920 may not be directlyexecutable by the processor module 905 but cause a computer (e.g., whencompiled and executed) to perform functions described herein. Theprocessor module 905 may include an intelligent hardware device, (e.g.,a central processing unit (CPU), a microcontroller, an ASIC, etc.)

FIG. 10 shows a diagram of a system 1000 including a base station 105configured for PUCCH with MTC devices in accordance with various aspectsof the present disclosure. System 1000 may include base station 105-d,which may be an example of a wireless device 600, a wireless device 700,or a base station 105 as described above with reference to FIGS. 1-8.Base station 105-d may include a base station PUCCH module 1010, whichmay be an example of a base station PUCCH module 1010 described withreference to FIGS. 7-9. Base station 105-d may also include componentsfor bi-directional voice and data communications including componentsfor transmitting communications and components for receivingcommunications. For example, base station 105-d may communicatebi-directionally with UE 115-f (which may be an MTC device) or UE 115-g.

In some cases, base station 105-d may have one or more wired backhaullinks. Base station 105-d may have a wired backhaul link (e.g., S1interface, etc.) to the core network 130. Base station 105-d may alsocommunicate with other base stations 105, such as base station 105-e andbase station 105-f via inter-base station backhaul links (e.g., an X2interface). Each of the base stations 105 may communicate with UEs 115using the same or different wireless communications technologies. Insome cases, base station 105-d may communicate with other base stationssuch as 105-e or 105-f utilizing base station communications module1025. In some embodiments, base station communications module 1025 mayprovide an X2 interface within an LTE/LTE-A wireless communicationnetwork technology to provide communication between some of the basestations 105. In some embodiments, base station 105-d may communicatewith other base stations through core network 130. In some cases, basestation 105-d may communicate with the core network 130 through networkcommunications module 1030.

The base station 105-d may include a processor module 1005, memory 1015(including software (SW) 1020), transceiver modules 1035, and antenna(s)1040, which each may be in communication, directly or indirectly, withone another (e.g., over bus system 1045). The transceiver modules 1035may be configured to communicate bi-directionally, via the antenna(s)1040, with the UEs 115, which may be multi-mode devices. The transceivermodule 1035 (or other components of the base station 105-d) may also beconfigured to communicate bi-directionally, via the antennas 1040, withone or more other base stations (not shown). The transceiver module 1035may include a modem configured to modulate the packets and provide themodulated packets to the antennas 1040 for transmission, and todemodulate packets received from the antennas 1040. Base station 105-dmay include multiple transceiver modules 1035, each with one or moreassociated antennas 1040. The transceiver module may be an example of acombined receiver 605 and transmitter 615 of FIG. 6.

The memory 1015 may include RAM and ROM. The memory 1015 may also storecomputer-readable, computer-executable software code 1020 containinginstructions that are configured to, when executed, cause the processormodule 1010 to perform various functions described herein (e.g., PUCCHfor MTC devices, selecting coverage enhancement techniques, callprocessing, database management, message routing, etc.). Alternatively,the software 1020 may not be directly executable by the processor module1005 but be configured to cause the computer, e.g., when compiled andexecuted, to perform functions described herein. The processor module1005 may include an intelligent hardware device, e.g., a CPU, amicrocontroller, an ASIC, etc. The processor module 1005 may includevarious special purpose processors such as encoders, queue processingmodules, base band processors, radio head controllers, digital signalprocessor (DSPs), and the like.

The base station communications module 1025 may manage communicationswith other base stations 105. The communications management module mayinclude a controller or scheduler for controlling communications withUEs 115 in cooperation with other base stations 105. For example, thebase station communications module 1025 may coordinate scheduling fortransmissions to UEs 115 for various interference mitigation techniquessuch as beamforming or joint transmission.

FIG. 11 shows a flowchart illustrating a method 1100 for PUCCH with MTCdevices in accordance with various aspects of the present disclosure.The operations of method 1100 may be implemented by a wireless device(e.g., a UE 115, a wireless device 600, or a wireless device 700) or itscomponents as described with reference to FIGS. 1-10. For example, theoperations of method 1100 may be performed by the PUCCH module 610 asdescribed with reference to FIGS. 6-9. In some examples, a wirelessdevice may execute a set of codes to control the functional elements ofthe wireless device to perform the functions described below.Additionally or alternatively, the wireless device may perform aspectsthe functions described below using special-purpose hardware.

At block 1105, the wireless device may identify a TTI bundling parameterof an UL control channel as described above with reference to FIGS. 1-5.In certain examples, the operations of block 1105 may be performed bythe bundling parameter module 705 as described above with reference toFIG. 7.

At block 1110, the wireless device may identify one or more resourcesfor the UL control channel based at least in part on the TTI bundlingparameter as described above with reference to FIGS. 1-5. In certainexamples, the operations of block 1110 may be performed by the ULcontrol resource module 710 as described above with reference to FIG. 7.

At block 1115, the wireless device may transmit the UL control channelusing the one or more resources as described above with reference toFIGS. 1-5. In certain examples, the operations of block 1115 may beperformed by the transmitter 615 as described above with reference toFIG. 6.

FIG. 12 shows a flowchart illustrating a method 1200 for PUCCH with MTCdevices in accordance with various aspects of the present disclosure.The operations of method 1200 may be implemented by a wireless device(e.g., a base station 105, a wireless device 600, or a wireless device700) or its components as described with reference to FIGS. 1-10. Forexample, the operations of method 1200 may be performed by the PUCCHmodule 610 as described with reference to FIGS. 6-9. In some examples, awireless device may execute a set of codes to control the functionalelements of the wireless device to perform the functions describedbelow. Additionally or alternatively, the wireless device may performaspects the functions described below using special-purpose hardware.The method 1200 may also incorporate aspects of method 1100 of FIG. 11.

At block 1205, the wireless device may identify a TTI bundling parameterof an UL control channel as described above with reference to FIGS. 1-5.In certain examples, the operations of block 1205 may be performed bythe bundling parameter module 705 as described above with reference toFIG. 7.

At block 1210, the wireless device may identify one or more resourcesfor the UL control channel based at least in part on the TTI bundlingparameter as described above with reference to FIGS. 1-5. In certainexamples, the operations of block 1210 may be performed by the ULcontrol resource module 710 as described above with reference to FIG. 7.

At block 1215, the wireless device may receive the UL control channelusing the one or more resources as described above with reference toFIGS. 1-5. In certain examples, the operations of block 1215 may beperformed by the receiver 605 as described above with reference to FIG.6.

FIG. 13 shows a flowchart illustrating a method 1300 for PUCCH with MTCdevices in accordance with various aspects of the present disclosure.The operations of method 1300 may be implemented by a wireless device(e.g., a UE 115, a wireless device 600 or a wireless device 700) or itscomponents as described with reference to FIGS. 1-10. For example, theoperations of method 1300 may be performed by the PUCCH module 610 asdescribed with reference to FIGS. 6-9. In some examples, a wirelessdevice may execute a set of codes to control the functional elements ofthe wireless device to perform the functions described below.Additionally or alternatively, the wireless device may perform aspectsthe functions described below using special-purpose hardware. The method1300 may also incorporate aspects of methods 1100 and 1200 of FIGS.11-12.

At block 1305, the wireless device may identify a TTI bundling parameterof an UL control channel as described above with reference to FIGS. 1-5.In certain examples, the operations of block 1305 may be performed bythe bundling parameter module 705 as described above with reference toFIG. 7.

At block 1310, the wireless device may identify one or more resourcesfor the UL control channel based at least in part on the TTI bundlingparameter as described above with reference to FIGS. 1-5. For example,the wireless device may receive a configuration of a plurality ofresources for the TTI bundling parameter as described above withreference to FIGS. 1-5. In certain examples, the operations of block1310 may be performed by the receiver 605 as described above withreference to FIG. 6.

At block 1315, the wireless device may receive an indication in a DLcontrol channel as described above with reference to FIGS. 1-5. Incertain examples, the operations of block 1315 may be performed by thereceiver 605 as described above with reference to FIG. 6.

At block 1320, the wireless device may identify one resource from theconfigured plurality of resources for the TTI bundling parameter basedon the indication as described above with reference to FIGS. 1-5. Incertain examples, the operations of block 1320 may be performed by theresource selection module 820 as described above with reference to FIG.8.

FIG. 14 shows a flowchart illustrating a method 1400 for PUCCH with MTCdevices in accordance with various aspects of the present disclosure.The operations of method 1400 may be implemented by a wireless device(e.g., a UE 115, a wireless device 600 or a wireless device 700) or itscomponents as described with reference to FIGS. 1-10. For example, theoperations of method 1400 may be performed by the PUCCH module 610 asdescribed with reference to FIGS. 6-9. In some examples, a wirelessdevice may execute a set of codes to control the functional elements ofthe wireless device to perform the functions described below.Additionally or alternatively, the wireless device may perform aspectsthe functions described below using special-purpose hardware. The method1400 may also incorporate aspects of methods 1100, 1200, and 1300 ofFIGS. 11-13.

At block 1405, the wireless device may identify a TTI bundling parameterof an UL control channel as described above with reference to FIGS. 1-5.In certain examples, the operations of block 1405 may be performed bythe bundling parameter module 705 as described above with reference toFIG. 7.

At block 1410, the wireless device may identify a DCI format based atleast in part on the TTI bundling parameter as described above withreference to FIGS. 1-5. In certain examples, the operations of block1410 may be performed by the DCI format module 830 as described abovewith reference to FIG. 8.

At block 1415, the wireless device may receive a DL control channelbased at least in part on the DCI format as described above withreference to FIGS. 1-5. In certain examples, the operations of block1415 may be performed by the receiver 605 as described above withreference to FIG. 6.

FIG. 15 shows a flowchart illustrating a method 1500 for PUCCH with MTCdevices in accordance with various aspects of the present disclosure.The operations of method 1500 may be implemented by a wireless device(e.g., a base station 105, a wireless device 600, or a wireless device700) or its components as described with reference to FIGS. 1-10. Forexample, the operations of method 1500 may be performed by the PUCCHmodule 610 as described with reference to FIGS. 6-9. In some examples, awireless device may execute a set of codes to control the functionalelements of the wireless device to perform the functions describedbelow. Additionally or alternatively, the wireless device may performaspects the functions described below using special-purpose hardware.The method 1500 may also incorporate aspects of methods 1100, 1200,1300, and 1400 of FIGS. 11-14.

At block 1505, the wireless device may identify a TTI bundling parameterof an UL control channel as described above with reference to FIGS. 1-5.In certain examples, the operations of block 1505 may be performed bythe bundling parameter module 705 as described above with reference toFIG. 7.

At block 1510, the wireless device may identify a DCI format based atleast in part on the TTI bundling parameter as described above withreference to FIGS. 1-5. In certain examples, the operations of block1510 may be performed by the DCI format module 830 as described abovewith reference to FIG. 8.

At block 1515, the wireless device may transmit a DL control channelbased at least in part on the DCI format as described above withreference to FIGS. 1-5. In certain examples, the operations of block1515 may be performed by the transmitter 615 as described above withreference to FIG. 6.

FIG. 16 shows a flowchart illustrating a method 1600 for PUCCH with MTCdevices in accordance with various aspects of the present disclosure.The operations of method 1600 may be implemented by a wireless device(e.g., a UE 115, a wireless device 600, or a wireless device 700) or itscomponents as described with reference to FIGS. 1-10. For example, theoperations of method 1600 may be performed by the PUCCH module 610 asdescribed with reference to FIGS. 6-9. In some examples, a wirelessdevice may execute a set of codes to control the functional elements ofthe wireless device to perform the functions described below.Additionally or alternatively, the wireless device may perform aspectsthe functions described below using special-purpose hardware. The method1600 may also incorporate aspects of methods 1100, 1200, 1300, 1400, and1500 of FIGS. 11-15.

At block 1605, the wireless device may identify a TTI bundling parameterof an UL control channel as described above with reference to FIGS. 1-5.The TTI bundling parameter may correspond to an MCS information field,wherein the DCI format is based at least in part on the MCS informationfield. For example, the wireless device may determine a first TTIbundling length. In certain examples, the operations of block 1605 maybe performed by the bundling parameter module 705 as described abovewith reference to FIG. 7.

At block 1610, the wireless device may identify a DCI format based atleast in part on the TTI bundling parameter as described above withreference to FIGS. 1-5. For example, the wireless device may determine afirst length of the MCS information field based on the first TTIbundling length as described above with reference to FIGS. 1-5. Incertain examples, the operations of block 1610 may be performed by theMCS information field module 840 as described above with reference toFIG. 8.

At block 1615, the wireless device may determine a second TTI bundlinglength, where the second TTI bundling length is larger than the firstTTI bundling length as described above with reference to FIGS. 1-5. Incertain examples, the operations of block 1615 may be performed by thebundling parameter module 705 as described above with reference to FIG.7.

At block 1620, the wireless device may determine a second length of theMCS information field based on the second TTI bundling length, where thesecond length of the MCS information field is smaller than the firstlength of the MCS information field as described above with reference toFIGS. 1-5. In certain examples, the operations of block 1620 may beperformed by the MCS information field module 840 as described abovewith reference to FIG. 8.

Thus, methods 1100, 1200, 1300, 1400, 1500, and 1600 may provide forPUCCH with MTC devices. It should be noted that methods 1100, 1200,1300, 1400, 1500, and 1600 describe possible implementations, and thatthe operations and the steps may be rearranged or otherwise modifiedsuch that other implementations are possible. In some examples, aspectsfrom two or more of the methods 1100, 1200, 1300, 1400, 1500, and 1600may be combined.

The detailed description set forth above in connection with the appendeddrawings describes exemplary embodiments and does not represent all theembodiments that may be implemented or that are within the scope of theclaims. The term “exemplary” used throughout this description means“serving as an example, instance, or illustration,” and not “preferred”or “advantageous over other embodiments.” The detailed descriptionincludes specific details for the purpose of providing an understandingof the described techniques. These techniques, however, may be practicedwithout these specific details. In some instances, well-known structuresand devices are shown in block diagram form in order to avoid obscuringthe concepts of the described embodiments.

Information and signals may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the above description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof.

The various illustrative blocks and modules described in connection withthe disclosure herein may be implemented or performed with ageneral-purpose processor, a DSP, an ASIC, an FPGA or other programmablelogic device, discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. A general-purpose processor may be a microprocessor,but in the alternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices (e.g., a combinationof a DSP and a microprocessor, multiple microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration).

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope of the disclosure and appended claims. For example, due to thenature of software, functions described above can be implemented usingsoftware executed by a processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations. Also, as used herein, including in the claims, “or” as usedin a list of items (for example, a list of items prefaced by a phrasesuch as “at least one of” or “one or more of”) indicates an inclusivelist such that, for example, a list of [at least one of A, B, or C]means A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

Computer-readable media includes both non-transitory computer storagemedia and communication media including any medium that facilitatestransfer of a computer program from one place to another. Anon-transitory storage medium may be any available medium that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, non-transitory computer-readable media cancomprise RAM, ROM, electrically erasable programmable read only memory(EEPROM), compact disk (CD) ROM or other optical disk storage, magneticdisk storage or other magnetic storage devices, or any othernon-transitory medium that can be used to carry or store desired programcode means in the form of instructions or data structures and that canbe accessed by a general-purpose or special-purpose computer, or ageneral-purpose or special-purpose processor. Also, any connection isproperly termed a computer-readable medium. For example, if the softwareis transmitted from a website, server, or other remote source using acoaxial cable, fiber optic cable, twisted pair, digital subscriber line(DSL), or wireless technologies such as infrared, radio, and microwave,then the coaxial cable, fiber optic cable, twisted pair, DSL, orwireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,include CD, laser disc, optical disc, digital versatile disc (DVD),floppy disk and Blu-ray disc where disks usually reproduce datamagnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

The previous description of the disclosure is provided to enable aperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the scope of thedisclosure. Thus, the disclosure is not to be limited to the examplesand designs described herein but is to be accorded the broadest scopeconsistent with the principles and novel features disclosed herein.

Techniques described herein may be used for various wirelesscommunications systems such as code division multiple access (CDMA),time division multiple access (TDMA), frequency division multiple access(FDMA), OFDMA, SC-FDMA, and other systems. The terms “system” and“network” are often used interchangeably. A CDMA system may implement aradio technology such as CDMA2000, Universal Terrestrial Radio Access(UTRA), etc. CDMA2000 covers IS-2000, IS-95, and IS-856 standards.IS-2000 Releases 0 and A are commonly referred to as CDMA2000 1×, 1×,etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1×EV-DO, HighRate Packet Data (HRPD), etc. UTRA includes Wideband CDMA (WCDMA) andother variants of CDMA. A TDMA system may implement a radio technologysuch as Global System for Mobile Communications (GSM). An OFDMA systemmay implement a radio technology such as Ultra Mobile Broadband (UMB),Evolved UTRA (E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal MobileTelecommunications system (UMTS). 3GPP Long Term Evolution (LTE) andLTE-Advanced (LTE-A) are new releases of Universal MobileTelecommunications System (UMTS) that use E-UTRA. UTRA, E-UTRA, UMTS,LTE, LTE-A, and Global System for Mobile communications (GSM) aredescribed in documents from an organization named “3rd GenerationPartnership Project” (3GPP). CDMA2000 and UMB are described in documentsfrom an organization named “3rd Generation Partnership Project 2”(3GPP2). The techniques described herein may be used for the systems andradio technologies mentioned above as well as other systems and radiotechnologies. The description above, however, describes an LTE systemfor purposes of example, and LTE terminology is used in much of thedescription above, although the techniques are applicable beyond LTEapplications.

What is claimed is:
 1. A method of wireless communication at a basestation, comprising: transmitting an indication of a coverageenhancement (CE) level for a user equipment (UE); identifying, based atleast in part on the indication, one downlink control information (DCI)format of a plurality of DCI formats, the plurality of DCI formatscomprising: a first DCI format corresponding to a first CE level,wherein the first DCI format indicates a first configuration forconveying DCI and comprises a first resource allocation field that has afirst length, a second DCI format corresponding to a second CE level,wherein the second DCI format indicates a different configuration forconveying DCI than the first DCI format and comprises a second resourceallocation field that has a second length that is different than thefirst length, and a third DCI format corresponding to a third CE level,wherein the third CE level indicates a lack of coverage enhancements,and wherein the third DCI format indicates a third configuration forconveying DCI and comprises a third resource allocation field that has athird length; and transmitting, to the UE on a downlink control channel,DCI comprising a resource allocation field according to the identifiedDCI format.
 2. The method of claim 1, wherein the CE level correspondsto a resource allocation granularity level, and wherein the identifiedDCI format is based at least in part on the resource allocationgranularity level.
 3. The method of claim 1, wherein the CE levelcorresponds to a modulation and coding scheme (MCS) information field,and wherein the identified DCI format is based at least in part on theMCS information field.
 4. The method of claim 1, further comprising:determining a first transmission time interval (TTI) bundling length;determining a first length of a first MCS information field of the firstDCI format based on the first TTI bundling length; determining a secondTTI bundling length, wherein the second TTI bundling length is largerthan the first TTI bundling length; and determining a second length of asecond MCS information field of the second DCI format based on thesecond TTI bundling length, wherein the second length of the second MCSinformation field is smaller than the first length of the first MCSinformation field.
 5. The method of claim 1, wherein the CE levelcomprises a transmission time interval (TTI) bundling level.
 6. Themethod of claim 1, further comprising: determining a correspondencebetween the first DCI format and the first CE level and the second DCIformat and the second CE level, wherein the one of the first DCI formator the second DCI format is identified based at least in part on thecorrespondence.
 7. The method of claim 1, wherein the indication of theCE level indicates the first CE level, wherein the first DCI format isidentified based at least in part on the first CE level being indicated,and wherein the DCI comprising the resource allocation field of thefirst length is transmitted according to the first DCI format based atleast in part on the identifying.
 8. The method of claim 1, wherein theidentifying comprises: identifying the first DCI format when theindication of the CE level for the UE indicates the first CE level,wherein DCI comprising the resource allocation field of the first lengthis transmitted according to the first DCI format based at least in parton identifying the first DCI format; or identifying the second DCIformat when the indication of the CE level for the UE indicates thesecond CE level, wherein DCI comprising the resource allocation field ofthe second length is transmitted according to the second DCI formatbased at least in part on identifying the second DCI format.
 9. Themethod of claim 1, wherein: the first CE level corresponds to a firstresource allocation granularity level, and wherein the first resourceallocation field of the first DCI format comprises a first number ofbits to indicate a first resource allocation based at least in part onthe first resource allocation granularity level, and the second CE levelcorresponds to a second resource allocation granularity level, andwherein the second resource allocation field of the second DCI formatcomprises a second number of bits that is less than the first number ofbits to indicate a second resource allocation based at least in part onthe second resource allocation granularity level.
 10. An apparatus forwireless communication at a base station, comprising: a processor;memory coupled with the processor; and instructions stored in the memoryand executable by the processor to cause the apparatus to: transmit anindication of a coverage enhancement (CE) level for a user equipment(UE); identify, based at least in part on the indication, one downlinkcontrol information (DCI) format of a plurality of DCI formats, theplurality of DCI formats comprising: a first DCI format corresponding toa first CE level, wherein the first DCI format indicates a firstconfiguration for conveying DCI and comprises a first resourceallocation field that has a first length, a second DCI formatcorresponding to a second CE level, wherein the second DCI formatindicates a different configuration for conveying DCI than the first DCIformat and comprises a second resource allocation field that has asecond length that is different than the first length, and a third DCIformat corresponding to a third CE level, wherein the third CE levelindicates a lack of coverage enhancements, and wherein the third DCIformat indicates a third configuration for conveying DCI and comprises athird resource allocation field that has a third length; and transmit,to the UE on a downlink control channel, DCI comprising a resourceallocation field according to the identified DCI format.
 11. Theapparatus of claim 10, wherein the CE level corresponds to a resourceallocation granularity level, and wherein the identified DCI format isbased at least in part on the resource allocation granularity level. 12.The apparatus of claim 10, wherein the CE level corresponds to amodulation and coding scheme (MCS) information field, and wherein theidentified DCI format is based at least in part on the MCS informationfield.
 13. The apparatus of claim 10, wherein the instructions arefurther executable by the processor to cause the apparatus to: determinea first transmission time interval (TTI) bundling length; determine afirst length of a first MCS information field of the first DCI formatbased on the first TTI bundling length; determine a second TTI bundlinglength, wherein the second TTI bundling length is larger than the firstTTI bundling length; and determine a second length of a second MCSinformation field of the second DCI format based on the second TTIbundling length, wherein the second length of the second MCS informationfield is smaller than the first length of the first MCS informationfield.
 14. The apparatus of claim 10, wherein the CE level comprises atransmission time interval (TTI) bundling level.
 15. The apparatus ofclaim 10, wherein the instructions are further executable by theprocessor to cause the apparatus to: determine a correspondence betweenthe first DCI format and the first CE level and the second DCI formatand the second CE level, wherein the one of the first DCI format or thesecond DCI format is identified based at least in part on thecorrespondence.
 16. The apparatus of claim 10, wherein the indication ofthe CE level indicates the first CE level, wherein the first DCI formatis identified based at least in part on the first CE level beingindicated, and wherein the DCI comprising the resource allocation fieldof the first length is transmitted according to the first DCI formatbased at least in part on the identifying.
 17. The apparatus of claim10, wherein the instructions for identifying the one DCI format arefurther executable by the processor to cause the apparatus to: identifythe first DCI format when the indication of the CE level for the UEindicates the first CE level, wherein DCI comprising the resourceallocation field of the first length is transmitted according to thefirst DCI format based at least in part on identifying the first DCIformat; or identify the second DCI format when the indication of the CElevel for the UE indicates the second CE level, wherein DCI comprisingthe resource allocation field of the second length is transmittedaccording to the second DCI format based at least in part on identifyingthe second DCI format.
 18. The apparatus of claim 10, wherein: the firstCE level corresponds to a first resource allocation granularity level,and wherein the first resource allocation field of the first DCI formatcomprises a first number of bits to indicate a first resource allocationbased at least in part on the first resource allocation granularitylevel, and the second CE level corresponds to a second resourceallocation granularity level, and wherein the second resource allocationfield of the second DCI format comprises a second number of bits that isless than the first number of bits to indicate a second resourceallocation based at least in part on the second resource allocationgranularity level.
 19. An apparatus for wireless communication at a basestation, comprising: means for transmitting an indication of a coverageenhancement (CE) level for a user equipment (UE); means for identifying,based at least in part on the indication, one downlink controlinformation (DCI) format of a plurality of DCI formats, the plurality ofDCI formats comprising: a first DCI format corresponding to a first CElevel, wherein the first DCI format indicates a first configuration forconveying DCI and comprises a first resource allocation field that has afirst length, a second DCI format corresponding to a second CE level,wherein the second DCI format indicates a different configuration forconveying DCI than the first DCI format and comprises a second resourceallocation field that has a second length that is different than thefirst length, and a third DCI format corresponding to a third CE level,wherein the third CE level indicates a lack of coverage enhancements,and wherein the third DCI format indicates a third configuration forconveying DCI and comprises a third resource allocation field that has athird length; and means for transmitting, to the UE on a downlinkcontrol channel, DCI comprising a resource allocation field according tothe identified DCI format.
 20. The apparatus of claim 19, wherein the CElevel corresponds to a resource allocation granularity level, andwherein the identified DCI format is based at least in part on theresource allocation granularity level.
 21. The apparatus of claim 19,wherein the CE level corresponds to a modulation and coding scheme (MCS)information field, and wherein the identified DCI format is based atleast in part on the MCS information field.
 22. The apparatus of claim19, further comprising: means for determining a first transmission timeinterval (TTI) bundling length; means for determining a first length ofa first MCS information field of the first DCI format based on the firstTTI bundling length; means for determining a second TTI bundling length,wherein the second TTI bundling length is larger than the first TTIbundling length; and means for determining a second length of a secondMCS information field of the second DCI format based on the second TTIbundling length, wherein the second length of the second MCS informationfield is smaller than the first length of the first MCS informationfield.
 23. The apparatus of claim 19, wherein the CE level comprises atransmission time interval (TTI) bundling level.
 24. The apparatus ofclaim 19, further comprising: means for determining a correspondencebetween the first DCI format and the first CE level and the second DCIformat and the second CE level, wherein the one of the first DCI formator the second DCI format is identified based at least in part on thecorrespondence.
 25. The apparatus of claim 19, wherein the indication ofthe CE level indicates the first CE level, wherein the first DCI formatis identified based at least in part on the first CE level beingindicated, and wherein the DCI comprising the resource allocation fieldof the first length is transmitted according to the first DCI formatbased at least in part on the identifying.
 26. The apparatus of claim19, wherein the identifying comprises: means for identifying the firstDCI format when the indication of the CE level for the UE indicates thefirst CE level, wherein DCI comprising the resource allocation field ofthe first length is transmitted according to the first DCI format basedat least in part on identifying the first DCI format; or means foridentifying the second DCI format when the indication of the CE levelfor the UE indicates the second CE level, wherein DCI comprising theresource allocation field of the second length is transmitted accordingto the second DCI format based at least in part on identifying thesecond DCI format.
 27. The apparatus of claim 19, wherein: the first CElevel corresponds to a first resource allocation granularity level, andwherein the first resource allocation field of the first DCI formatcomprises a first number of bits to indicate a first resource allocationbased at least in part on the first resource allocation granularitylevel, and the second CE level corresponds to a second resourceallocation granularity level, and wherein the second resource allocationfield of the second DCI format comprises a second number of bits that isless than the first number of bits to indicate a second resourceallocation based at least in part on the second resource allocationgranularity level.
 28. A non-transitory computer-readable medium storingcode for wireless communications at a network, the code comprisinginstructions executable by a processor to: transmit an indication of acoverage enhancement (CE) level for a user equipment (UE); identify,based at least in part on the indication, one downlink controlinformation (DCI) format of a plurality of DCI formats, the plurality ofDCI formats comprising: a first DCI format corresponding to a first CElevel, wherein the first DCI format indicates a first configuration forconveying DCI and comprises a first resource allocation field that has afirst length, a second DCI format corresponding to a second CE level,wherein the second DCI format indicates a different configuration forconveying DCI than the first DCI format and comprises a second resourceallocation field that has a second length that is different than thefirst length, and a third DCI format corresponding to a third CE level,wherein the third CE level indicates a lack of coverage enhancements,and wherein the third DCI format indicates a third configuration forconveying DCI and comprises a third resource allocation field that has athird length; and transmit, to the UE on a downlink control channel, DCIcomprising a resource allocation field according to the identified DCIformat.
 29. The non-transitory computer-readable medium of claim 28,wherein the CE level corresponds to a resource allocation granularitylevel, and wherein the identified DCI format is based at least in parton the resource allocation granularity level.
 30. The non-transitorycomputer-readable medium of claim 28, wherein the CE level correspondsto a modulation and coding scheme (MCS) information field, and whereinthe identified DCI format is based at least in part on the MCSinformation field.